Late departures in the fall have been observed at St. George Island, October 3; and St. Paul Island November 16. Early fall arrivals have been noted on the Alaskan coast at Igiak Bay, July 23; Tigalda Island, August 5; Unimak, August 14; and Dexter, Norton Sound, August 29. _Egg dates._--Pribilof Island: 32 records, May 6 to July 2; 16 records, May 30 to June 11. ARQUATELLA PTILOCNEMIS COUESI (Ridgway) ALEUTIAN SANDPIPER HABITS I prefer the above scientific name to the Check List name, because I can not believe that the Aleutian sandpiper is a subspecies of the purple sandpiper. The Aleutian sandpiper was originally described by Robert Ridgway (1880) as a distinct species. Later it was treated, and still stands on our Check List, as a subspecies of the purple sandpiper, because it somewhat resembles it in its winter plumage. In Mr. Ridgway's (1919) latest work, he treats it as a subspecies of the Pribilof sandpiper, a closely related form, which had been previously described; he there describes it as "similar to _A. p. ptilocnemis_ but decidedly smaller and much darker in color; the summer plumage with blackish and rusty or cinnamon-rufous predominating on back and scapulars, and all the colors much darker and more extended. Very similar in winter plumage to _A. maritima_, but summer plumage and young very different, both being conspicuously marked with rusty on back and scapulars, and the summer plumage with breast conspicuously blotched or clouded with dusky." Among a series of 11 birds of this species, which we collected on Attu Island, at the extreme western end of the Aleutian Chain, on June 23, 1911, are two birds which closely resemble _ptilocnemis_ in color, but in size are typical of _couesi_. At least one of them was a breeding bird, the parent of a brood of downy young, and doubtless both of them were summer resident birds. Dr. Ernst Hartert (1920) has described the resident bird of the Commander Islands as a distinct subspecies, under the name _Erolia maritima quarta_, of which he says: "In full summer plumage the feather-edgings are broader than in any other form and brighter, more rusty red, so that the rusty red seems to predominate on the whole of the upper parts." This description seems to fit our two birds from Attu Island very well; so that, if _quarta_ is a recognizable form, as it seems to be, this subspecies should be added to our North American list. The birds could easily fly across from the Commander Islands to Attu Island and establish themselves there.